If you're currently playing Guild Wars 2 on macOS, I'm afraid I have some bad news to deliver. Due to technical problems that have been brewing for a few years now, ArenaNet will be shutting down support for the macOS client on February 18, 2021.
"In 2018, Apple ended support for the OpenGL graphics technology that Guild Wars 2 uses on the Mac," explains the brief update. "While games and other software that rely on OpenGL still work for now, Apple has made it clear that this will not always be the case in new OS versions. They have also stopped actively fixing problems on Mac OS related to OpenGL, including graphics hardware driver issues."
"Earlier in 2020, Apple announced that future Mac computers will be designed around a different chip technology than the Intel processors used today. For now, OpenGL still works, and existing Mac computers based on Intel chips still work as well. At some point in the future, however, OpenGL may simply no longer be included on Mac systems at all, and the differences in chip hardware will make it very costly and difficult for us to support both the old and new processor designs."
"Starting February 18 , we will be discontinuing support for the Mac OS version of Guild Wars 2. This means the Mac client will no longer work after this date. We will also be turning off Gem purchases in the Mac version of the game beginning on January 19, the date of our next build in the new year."
The one bit of good news is that this will not impact your account in any way. As such, should you eventually swap to the Windows version of Guild Wars 2, you'll be able to continue right from where you left off as if nothing happened.
If that is simply not possible, it's also worth mentioning that ArenaNet is currently offering refunds for anyone affected. You will be able to refund purchases within a 30 day window of the refund request, so if this is something you wish to pursue, it might be wise to do so sooner rather than later.
You can read a little bit more about the fate of the macOS version, as well as follow any future updates, over at the Guild Wars 2 website.